Do leaves placed then broken by hand cause adjacent leaves to decay?

I tested this using a debug stick, leaf blocks have a "persistent"-tag and it is set to true, when the leaf block is placed by a player. Breaking a leaf block next to it does not change this, so they stay persistent.

You can place leaf blocks that will break using one of these:

/setblock <pos> minecraft:oak_leaves{persistent:0}
/fill <from> <to> minecraft:oak_leaves{persistent:0}

You can get a debug stick with this command:

/give @s minecraft:debug_stick

Leaf blocks also have a "distance"-tag, which is used to determin if it will decay. Leaf blocks with a distance of 7 do not count as part of a tree and will decay, unless they are "persistent".

A leaf block that touches a log block will have a "distance" of 1, any leaf block that touches the first leaf block, but no log block, will have a "distance" of 2, and so on.

The distance cannot be greater than 7. The persistence does not get updated when you as the player break nearby leaf blocks, the distance does get updated though